Hey they are based in my city Valencia Spain, so guess it has to be good!To be honest it may be a dis-service to yourself to not learn how to master your tracks (I still suck at it) but if having no idea and/or being lazy this could be a good option.The good news is that it is free to master to MP3 and M4A formats. Making it easy to test the quality and later master into full Wav with some other additions as well as can be seen in the press release below:

MasteringBOX is proud to announce availability of its namesake MasteringBOX mastering app for Android devices — the world’s first mastering app for Android, actually, allowing musicians and amateur producers to master their tracks using only a smartphone or tablet… and all for free!

​MasteringBOX is an online mastering application with a smart artificial intelligence that can detect the dynamic and spectral characteristics of the track being mastered and apply appropriate adjustments, allowing amateurproducers and independent artists alike to master their song, podcast, or live recording.The innovative MasteringBOX mastering website (www.masteringbox.com) was launched in May 2015 and now any Android user can also access all of its features by downloading the MasteringBOX app for free from Google Play.MasteringBOX has recently made a remarkable number of improvements to its mastering engine, significantly enhancing sound quality in many different music styles due to better detection and processing.

Additionally, a whole new set of features have been introduced. Premium (PRO and Unlimited) account subscribers can use the ID3 Tag Editor to add song information — including title, artist, composer, and album — and also upload and crop an image for the song’s cover art. This feature is compatible with MP3 and M4A formats. Indeed, in addition to the WEB OPTIMIZED (MP3 320KBPS) and CD QUALITY WAV (16BIT/44.1KHZ) formats, users can now obtain a MOBILE OPTIMIZED (M4A 128KBPS) format master.All users can download their masters in MP3 and M4A formats for free while a premium subscription is required for WAV format masters. Meanwhile, there is also a new ‘pay-per-track’ option; occasional users can now order an individual master in WAV format — no need to subscribe to a premium account for this purpose.

Accessing premium MasteringBOX features — both in the Android app and the website itself --​is simply a case of signing up for a PRO account at a reasonable €9 EUR monthly subscription (equivalent to €7 EUR per month when paid annually) for up to three uncompressed CD QUALITY WAV (16BIT/44.1KHZ) masters per month, together with EQ Control and ID3 Tag Editor & Cover Art. Thereafter, those needing unlimited uncompressed CD QUALITY WAV(16BIT/44.1KHZ) masters could consider the Unlimited account option, offering exactly that in addition to everything else in the PRO account for €19 EUR per month (equivalent to €14 EUR per month when paid annually).

Can’t say fairer than that, surely?

Saying that, whatever paid-for monthly subscription a user may (or may not) opt for,rest assured that the MasteringBOX Android app accesses exactly the same features as the MasteringBOX online mastering application, such as Loudness Control, EQ Control, and ID3 Tag Editor & Cover Art.​Users can log in or create a new account, upload their track, preview the master with before-and-after comparison, check their orders, download any previous masters, and much more besides… and all from the comfort of their favorite Android device.

Mastering. Made Easy.

The MasteringBOX app will run on any smartphone or tablet running Android 4.1 (Jelly Bean) or higher; it is available in both English and Spanish and can be downloaded for free from the Google Play store here: